How much money would it really have cost? Worse case they conscript a dozen guys with plastic snow shovels to dump it onto the water. That would be very far from ideal, but a hell of a lot better than half the city blowing up.
If they paid a dozen guys double the minimum wage for Lebanon and it took a whole month, that would be about $10,000.
They were probably not deciding between moving the AN or twiddling their thumbs. They were likely faced with a thousand other prospective things to do, many of which seemed more important than the AN.
After all, the AN had been lying there without blowing up for years, so surely someone else is keeping tabs on that too.
----
What I'm saying is that it's easy in hindsight to see how stupid a decision was, but to the actors at the time they were facing a much more complicated situation with less obvious tradeoffs.
Until we accept this, we will only have finger-pointing blame assigned and accidents will keep happening, because we'll just install new humans in the same flawed system that created the accident.
Were you work has tons of explosives currently on fire and... you call the fire brigade and film? I seriously doubt just how many if anyone actually at the port day to day knew it was there.
Personally I'd rather destroy half the city instead of dumping 3000 tons of nitrates into the waterways. There's proper ways to do things and they don't have to very expensive.
If they paid a dozen guys double the minimum wage for Lebanon and it took a whole month, that would be about $10,000.